Old windows programmers may remember when they used to save  program initialization parameters in .ini files in windows  or program directory. In windows 95 and afterwards there is a system database  called registry. Registry is a big database that both  programs and windows itself use it to save initialization  and settings of programs. This solution eliminates the need for several ini files. The only point that you must consider is that registry database  is very sensitive. If you delete or damage a part of it can  make your windows useless. So you must work with it with care. You can also edit and view registry with regedit.exe program that comes with windows. (You can run it from command prompt) Windows 2000 stores its configuration information in a  database called the registry. Registry is created from  thousands of setting values. This setting values are  categorized in a tree of folders. These folders are called  keys. Setting values are inserted inside keys. Values have different types. REG_SZ is string type. REG_DWORD is long integer type. REG_BINARY is binary type.  You can save settings of your programs in registry database. In this article we want to see how we can create, read and  update registry keys and values in C++ Builder and Delphi. In C++ Builder and Delphi, there is a registry object. We  will use registry object methods and properties for modifying and reading registry. In this part of article we will see how we can read setting  values from registry database. Following function is a sample code for reading a value from  registry into a character string "gSerial". void ReadSerKey() { AnsiString temp; char gSerial[40]; TRegistry *Reg = new TRegistry(); Reg->RootKey = HKEY_LOCAL_MACHINE; if(Reg->KeyExists("SOFTWARE\\TestSoftware")) { try{ if(Reg->OpenKey("Software\\TestSoftware",FALSE)) { temp=Reg->ReadString("SERIAL"); strcpy(gSerial,temp.c_str()); Reg->CloseKey(); } else  ShowMessage("Can not open program serial key ."); Reg->CloseKey(); } catch(ERegistryException &E) { ShowMessage(E.Message); delete Reg; return; } } delete Reg; } 1- First of all we must create a Registry object in memory  using "new" command. 2- Registry database has five root keys. Five trees grow  from these five root keys. Root keys are: HKEY_CLASSES_ROOT HKEY_CURRENT_USER HKEY_LOCAL_MACHINE HKEY_USERS HKEY_CURRENT_CONFIG Before starting to work we must determine one of root keys  as starting point for the tree that our key is on it. In  this example our key is located on HKEY_LOCAL_MACHINE. Complete address of our key is:  HKEY_LOCAL_MACHINE\Software\TestSoftware  i.e. our key is TestSoftware. We have chosen the name  exactly as our software name. This will ease finding the  key. 3-Now we test to see if the key we want to read exists. If  the key exists we start reading setting values, otherwise  we delete registry object we created when starting this  function and leave the function. This is done using  "exists" method of registry object. 4- if the key exists we can open. We use try...catch to  prevent exceptions. We can open the key using "OpenKey"  method of registry object. 5- If opening the key was successful then we can use  "ReadString" method of registry object to read the value  "SERIAL" from registry key and put it inside an AnsiString  type and then copy it in an ordinary C type string array. 6- After all we will close the key. And before exit we must  delete registry key. In next issue of ezine we will see  sample codes for creating and writing registry keys and  values.